Ecology of Transgenic Crops

Concerns about risks posed by transgenic agricultural crops generally focus on direct risks to human health. There is, however, a set of potential ecological risks that bears equal scrutiny. Transgenic crops designed to resist or kill herbivores, for example, may spread their genes to non-crop species, producing virulent weed species. Likewise, these crops may negatively affect populations of beneficial insects, as was the case in the recent controversial finding that transgenic corn may increase mortality in monarch butterfly caterpillars. Assessing such risks is inherently difficult, but the impact of ignoring them could be devastating.